Indicator for cranes and the like



July 7, 1964 E. c. BREKELBAUM ETAL INDICATOR FOR CRANES AND THE LIKE 2 Sheets-Sheet 1 Filed July 24, 1962 FIG 8 FIG. 7

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y 1964 E. c. BREKELBAUM ETAL 3,139,988

INDICATOR FOR CRANES AND THE LIKE 2 Sheets-Sheet 2 Filed July 24, 1962 INVENTOR. ERWIN C. BREKELBNJM GEORGE C. NOLL GEORGE B. KLOS 8 JOHN D. NIELSEN Oberlin, [M0441 Domzlh;

ATTORNEYS United States Patent 3,139,988 INDICATOR FOR CRANES AND THE LHCE Erwin C. Brekelbaum, George C. Noll, and George B.

Klos, Elyria, and John D. Nielsen, Lorain, Oh o,

assignors to The Thew Shovel Company, Lorain, (than,

a corporation of Ohio Filed July 24, 1962, Ser. No. 212,090 10 Claims. (Cl. 212-39) This invention relates generally, as indicated, to an indicator for cranes and the like and more particularly to a boom position indicator for cranes of the type wherein the operator is remotely situated from the operating boom. More particularly, this invention constitutes certain improvements in a tower crane as exemplified by the disclosure of the copending application of John I. Jones et al., Serial No. 86,166, entitled Crane, filed January 31, 1961, now Patent No. 3,083,837.

In such application, there is disclosed the unique tower crane wherein the standard operating crane boom is pivotally attached to the peak of a tower boom fixed to the crane turntable which is mounted on a rubber tire carrier. In such a crane, the standard operating boom is thus elevated by the height of the tower and the foot of the operating boom may then be approximately 100 feet or more above the operator. Such cranes have been found to be particularly advantageous in the erection of buildings and especially in the pouring of concrete for floors or columns in the interior of a building. In such operations, a major portion of the operating boom may be obscured from the direct vision of the operator in addition to being substantially elevated from the operator. Accordingly, it is desirous to have some form of indicator readily visible to the operator which will convey to him the approximate angle of the operating boom which, of

course, is a direct factor in the reach or radius of the particular load such as a concrete pouring bucket.

It is accordingly a principal object of the present invention to provide a crane boom position indicator for an operator situated remotely therefrom.

A further principal object is the provision of a crane boom indicator which will convey to the operator the angulator position of the operating boom so that the operator will know approximately where his load is positioned without having direct visual access thereto.

Another object is the provision, in a tower crane of the type having a tower boom with an operating boom pivoted to the peak thereof, of an indicator relating to the operator at the foot of the tower the angular position of the operating boom.

Yet another object is a mechanism directly linked to the operating boom of such a crane which will convey to the operator an approximation of the operating boom angle.

A still further object is the provision of such mechanism which will not only give the operator such visual indication of the operating boom angle, but which will also operate a safety boom hoist throw-out when a maximum boom angle is obtained and which will also operate a safe load indicator, such maximum safe load varying directly with the angle of the operating boom.

Other objects and advantages of the present invention will become apparent as the following description proceeds.

To the accomplishment of the foregoing and related ends, the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail a certain illustrative embodiment of the invention, this being indicative, however, of but one of the various ways in which the principle of the invention may be employed.

3,139,988 Patented July 7, 1964 In said annexed drawings:

FIG. 1 is a side elevation of a tower crane of the type with which the present invention may be employed;

FIG. 2 is a fragmentary side elevation of such crane on a somewhat enlarged scale showing the employment of the present invention with the booms and the reeving system therefor shown in phantom lines;

FIG. 3 is a fragmentary enlarged elevation of a portion of the present invention taken from FIG. 2;

FIG. 4 is an enlarged fragmentary front elevation corresponding to FIG. 3 but taken substantially from the line 4-4 of FIG. 2;

FIG. 5 is an enlarged fragmentary section illustrating the safe load indicating mechanism taken substantially on the line 5-5 of FIG. 2;

FIG. 6 is an enlarged fragmentary detailed view of such safe load indicating mechanism;

FIG. 7 is a detail view taken substantially on the line 77 of FIG. 2; and

FIG. 8 is an enlarged fragmentary detailed view illustrating the connection between the support rod and the operating boom.

Referring now to the drawings and more particularly to FIG. 1, there is illustrated a tower crane of the type disclosed in the aforementioned Jones et al., application, Serial No. 86,166, now Patent No. 3,083,837. Such a machine comprises essentially a tower attachment for a standard rubber tire mounted crane thus aifording a substantial amount of mobility to the crane having substantially increased reach and load capacities especially useful in the construction of buildings. The crane is mounted on a carrier 1 which is supported on the ground 2 by means of rubber tires 3, such being at least eight in number as shown. On the carrier frame 1, there is provided a turntable 4 for the crane superstructure generally indicated at 5. Hydraulically operated Outriggers 6 and 7 may be employed quickly and easily to stabilize and level the machine at the desired site of operation. The crane operator will be positioned in the cab 8 within the superstructure 5 and such operator will control the positioning of the standard or operating boom 10, the foot of which is pivoted at 11 to the peak 12 of the tower boom 13. The foot of the tower boom is mounted on a special adapter on the superstructure frame as indicated at 14 and a mast 15 may be pin-connected between the tower 13 and the peak of the A-frame in the superstructure 5 rigidly securing the tower in its shown vertical position.

The reeving system shown generally at 17 extends about a harness 18 which is connected to a derricking line 19 which is in turn fixedly connected to the distal end of a lower mast 20 pivoted at 21 to the peak 12 of the tower boom 13. Pendant 23 connects the distal end of the lower mast 20 with the distal end of the upper mast 24 which is pivoted to the peak 12 of the tower as indicated at 25. Boom pendants 26 may then be employed to connect the distal end of the upper mast 24 with the peak 27 of the standard operating boom 10. Reeving system may then be employed to move the operating boom through the operating range from the phantom line position indicated at 29 to the full line position. A load supported from the peak of the standard operating boom may then be spotted on the top of a building under construction by the angular positioning of the operating boom 10.

It can now be seen that by employment of the tower attachment, the standard operating boom 10, which would normally be connected to the crane superstructure frame at 14, has been elevated by the height of the tower. The standard boom then has been displaced substantially from the view of the operator in the cab 8 by the height of the tower. In view of such displacement of the operator from the operating boom, an indicator conveying to the operator the approximate angular position of the opouter end of indicator 33 held by set screw 34 to vertically extending indicator tube 35. The indicator 33 may be provided with two vertically extending apertures, one to receive the indicator tube 35 and the other adjacent thereto to receive pull rod 37. The indicator tube is held firmly to the indicator by the set screw 34 and the pull rod 37 is freely slidable in the aperture in the indicator provided therefor. The indicator tube extends upwardly along the chord of the boom 13 through guide brackets 38, 39 and 40. Such brackets may each constitute angle members, one face of which is welded or otherwise secured to the chord of the tower boom and the other face being provided with an aperture slidably accommodating the tube 35 therein. A collar 42 may be secured to the tube 35 by means of set screw or the like fastener 43, such collar being provided with a hook or the like 44 for one end of a spring 45. The opposite end of the spring mechanism 45 may be secured to the bracket 38 as indicated, which is, of course, secured to the tower boom. In this manner, the spring 45 will tend continually to pull the tube 35 in a downward direction.

The top of the tube 35 has secured thereto a bracket 47 to which is pin-connected a crane overload indicator operating cable 48 and the main boom indicator operating cable 49. The cable 49 extends upwardly from the base section 50 of the tower boom 13 through the intermediate sections 51 and 52 into the peak section 53 (note FIG. 1). In such peak section, there is provided a pulley 55 mounted on a bracket 56 and again, such bracket may comprise an angle secured to a chord of the boom. Such pulley 55 may be mounted on a bushing 57 and shaft 58 provided with a grease fitting 59 as shown and secured to the bracket 56 in the manner indicated.

From the pulley 55, the cable 49 extends upwardly through the peak section 53 of the tower boom 13 and is secured by shackle 61 intermediate the ends of an indicator lever 62. The indicator lever 62 is freely pivotally mounted on the operating boom 10 adjacent the foot 11 thereof as shown at 63. The distal end of the lever 62 is pin-connected at 64 to a support rod 65 which extends through an enlarged opening 66 in the flange 67 of bracket 68 secured to the base section of the standard operating boom 10. A plurality of transverse apertures 69 in the outer end of the support rod 65 accommodate a roll pin or the like 70 providing an adjustably positionable back-up for a washer 71 or the like. In this manner, the operating length of the support rod 65 may be adjusted by positioning the roll pin in any selected one of the various transverse apertures.

Referring now especially to FIGS. 2, and 6, it will be seen that the cable 48 attached to the top of the indicator tube 35 is pin-connected to the distal end of an operating arm 72 which is secured as by a set screw or the like 73 to the end of the overload indicator operating tube 74. Such tube is mounted in brackets 75 and 76 secured to the rectangular section tubular members 77 and 78 which comprise the mast 15 locking the tower boom to the peak of the A-frame of the superstructure 5. Collars 79 and 80 secured inside the brackets 75 and 76 by means of set screws or the like serve properly to hold and space the tube with respect to such brackets. A relatively short indicator operating arm 81 may be secured to the tube 74 as by set screw 82 and a rod 83 extending from the distal end of such arm to the overload indicator as shown generally at 84 may be employed to operate the same in re- 4 sponse to the angular position of the standard operating boom 10.

Such overload indicator 84 may, for example, be of the type shown in Aitken US. Patent No. 2,988,040 interconnecting, for example, a fixed point 85 of the A-frame and sheave 86 of the reeving 17. Such overload indicating devices are employed in cranes to give a visible and/or audible warning to the operator when the load imposed upon the crane approaches that which is greater than the safe-load for the particular radius at which the machine is operating. Thus the safe-load is a function of the radius or in other words a function of the angular disposition of the operating boom 10. The rod 83 connected to the link 87 in the housing 88 may be employed to rotate a cam to adjust a movable fulcrum in the indicator housing to compensate for the radius of the load. Accordingly, as the operating boom elevates to the full line position shown in FIG. 1, the load that can be carried due to the smaller radius greatly increases. Since the indicator meas' ures the tension on line 19, for example, the safe-load is a function of this tension modified by the operating boom angle. Thus as the angle of the boom changes, the cable 48 and rod 83 and the interconnecting linkages automatically rotate the cam within the indicator housing compensating for the increased or decreased operating radius. A spring 89 may be secured between the operat ing arm 72 and a bracket 90 to maintain tension on the cable 48 in all operating positions of the mechanism. The second housing 91 shown interconnected to the first housing may contain a cam mechanism for use with overthe-side loads and can selectively be employed instead of the cam mechanism in housing 88.

It can now be seen that the spring mechanisms 89 and 45 will tend to pull downwardly the cable 49 pivoting the indicator arm lever 62 always in a clockwise direction as viewed in FIG. 2 pulling the rod 65 through the bracket 68 to maintain the washer 71 in engagement with such bracket 68 to maintain the washer 71 in engagement with such bracket. Thus as the angle of the boom 10 changes, the indicator tube 35 will move up and down positioning the indicator 33 along the indicator plate 30 to give the operator a visual indication of the angle of the boom and the operating radius, and such mechanism automatically will operate the cam in the overload indicator 84 changing the maximum safeload at which a further signal will be transmitted to the operator.

As a further safety measure, the pull rod 37 which extends freely through the indicator 33 is pivotally connected at 92 to an arm 93 clamped to the end of shaft 94. Such shaft may be mounted on bushings 95 and 96 adjacent the tower boom adapter 14. Between such bushings, there is mounted a boom throw-out crank 97 having a plate 98 on the end thereof adapted to engage a boom throw-out rod 99 which will force the boom operating lever automatically to kick out to disengage the hoisting mechanism for the boom 10 upon the obtaining of the maximum boom angle. Collars 101 and 102 may be secured to the pull rod on either side of the bracket 38 and it will be seen as the indicator 33 is elevated by the vertical upward movement of the indicator tube 35, the indicator 33 will engage the collar 102 pulling upwardly the rod 37 to move the arm 93 in a counterclockwise direction as viewed in FIG. 3 to cause the plate 98 to engage the throw-out rod 99 when the boom 10 has obtained its maximum angular elevation disengaging the boom hoist clutch. Kelly stop cables 104 may be connected between the tower boom at 105 and the operating boom at 106 further to ensure that the boom 10 will not be elevated past its full line position.

When erecting or lowering the tower boom 13, the standard operating boom 10 will be folded to lie adjacent and parallel to such tower. The standard operating boom will also be thus positioned during the movement of the carrier from one position to another at the,

downwardly about the boom foot pivot 11. Thus a lost motion connection is provided between the linkage and the operating boom. As the boom is elevated about the foot 11, the support rod will assume its position shown in FIG. v2 as the result of the pressure of springs 89 and 45.

As seen in FIG. 4, the indicator plate 30 may be divided vertically into plate sections which will preferably be each of a difierent color. For example, reading in ascending order, the various squares may be plain, red, black, yellow, blue, green, white, black, and the uppermost being red. It will, of course, be understood that instead of the square blocks of dilferent colors giving the operator an approximation of the boom angle, a scale may be employed more accurately to measure boom angle and thus the radius. In operation, the operator may by experience know that if the concrete bucket is to be deposited at radius of approximately 40 feet, the indicator will then be positioned between the black and white blocks near the top of the indicator plate by the proper positioning of the boom. The operator by experience will know that the area for pouring of concrete or the like is at approximately the position of one of the particular colored blocks.

To install and set the boom indicator linkage, an adjustment should be made by means of the threaded connection 110 shown in FIG. 6 between the rod and the crane safe-load indicator cam operating linkage. When the proper length of the rod 83 is obtained, all of the indicator linkage will be hooked up and the tower raised and locked in position. The standard operating boom will then be raised to its minimum radius position or the full line position indicated in FIG. 1. In such position, the minimum radius of 30 feet from the centerline of rotation of the turntable to the centerline of the hook block will be obtained. When in this position, the indicator 33 will then be set in the center of the topred block 111 and the set screw 34 may be employed to lock it in place on the indicator tube 35. The collar 102 will be positioned on the pull rod 37 so that the indicator 33 will force the throw-out rod 99 to kick out the boom lever in cab 8 when the guide or pointer is just entering the red area of the block 111 at the top of the indicator plate. As the indicator or pointer descends along the indicator plate, the pull rod 37 will drop with the top collar 101 supporting the pull rod on the bracket 38. Thus the pul rod is effective to operate the boom throw-out only as the indicator approaches the top red block with the pull rod 37 freely passing through the indicator during the remaining movement thereof.

It can now be seen that there is provided a boom position indicator for cranes which will present to the operator remotely situated from the operating boom a visual indication of the operating boom angle and thus the load radius. Moreover, the same linkage may be employed to operate the overload indicating mechanism to compensate such mechanism for changes in the boom angle. Also, the same mechanism may be employed with a lost motion connection to force the boom lever to kick out as the boom approaches its maximum elevation.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims or the equivalent of such be employed.

We, therefore, particularly point out and distinctly claim as our invention:

1. A crane comprising an operators cab, an operating boom adapted to be operated therefrom, an indicator visually accessible to said operators cab, means responsive to changes in position of said operating boom to move said indicator visually to convey to said operators cab the position of said boom, atowe r, means mounting said operating boom at the peak of said tower, said operators cab and "accordingly said indicator being at the base of said tower and thus substantially removed from said operating boom, and linkage means interconnecting said indicator and said operating boom operative to move said indicator in responseto changes in the angular position of said operating boom.

2. A crane comprising an operators cab, an operating boom adapted to be operated therefrom, an indicator visually accessible to said operators cab, means responsive to changes in position of said operating boom to move said indicator visually to convey to said operators cab the position of said boom, a tower, means mounting said operating boom at the peak of said tower, said operators cab and accordingly said indicator being at the base of said tower and thus substantially removed from said operating boom, linkage means interconnecting said indicator and said operating boom operative to move said indicator in response to changes in the angular position of said operating boom, and lost motion connection means in said linkage whereby said operating boom may be folded to lie parallel to said tower without affecting said linkage.

3. A crane comprising an operators cab, an operating boom adapted to be operated therefrom, an indicator visually accessible to said operators cab, means responsive to changes in position of said operating boom to move said indicator visually to convey to said operators cab the position of said boom, a tower, means mounting said operating boom at the peak of said tower, said operators cab and accordingly said indicator being at the base of said tower and thus substantially removed from said operating boom, linkage means interconnecting said indicator and said operating boom operative to move said indicator in response to changes in the angular position of said operating boom, and a crane overload indicator, said linkage means being also connected to said overload indicator to vary the maximum permitted load according to the operating boom angle.

4. A crane comprising an operators cab, an operating boom adapted to be operated therefrom, an indicator visually accessible to said operators cab, means responsive to changes in position of said operating boom to move said indicator visually to convey to said operators cab the position of said boom, a tower, means mounting said operating boom at the peak of said tower, said operators cab and accordingly said indicator being at the base of said tower and thus substantially removed from said operating boom, linkage means interconnecting said indicator and said operating boom operative to move said indicator in response to changes in the angular position of said operating boom, a boom hoist throw-out, and means responsive to the movement of said indicator to a position indicating maximum boom elevation to actuate said boom hoist throw-out to stop the boom hoist mechanism.

5. A crane comprising an operators cab, an operating boom adapted to be operated therefrom, an indicator visually accessible to said operators cab, means responsive to changes in position of said operating boom to move said indicator visually to convey to said operators cab the position of said boom, a tower, means mounting said operating boom at the peak of said tower, said operators cab being at the base of said tower and thus substantially removed from said operating boom, linkage means interconnecting said indicator and said operating boom operative vertically to move said indicator in response to changes in the angular position of said operating boom, said linkage means comprising a vertically movable indicator tube mounted on said tower, said indicator being secured to said indicator tube and movable therewith, and cable means connecting the top of said indicator tube with said operating boom operative vertically to move 7 said indicator tube and thus said indicator in response to angular changes in the position of said operating boom.

6. A crane as set forth in claim 5 including spring means operative actively to urge said indicator tube downwardly to maintain said cable under tension.

7. A crane as set forth in claim 6 including lost motion connection means connecting said cable to said operating boom whereby said operating boom may be folded to lie parallel to said tower without affecting said linkage.

8. A crane as set forth in claim 7 including a crane overload indicator, means connecting said indicator tube to said crane overload indicator operative to vary the maximum safe-load in response to changes in the angle of said operating boom.

9. A crane as set forth in claim 8 including a boom hoist throw-out, and means responsive to movement of References Cited in the file of this patent UNITED STATES PATENTS 2,030,529 Nash Feb. 11, 1936 2,374,298 Nasset Apr. 24, 1945 2,772,411 Cooper Nov. 27, 1956 15 2,988,040 Aitken June 13, 1961 

1. A CRANE COMPRISING AN OPERATOR''S CAB, AN OPERATING BOOM ADAPTED TO BE OPERATED THEREFROM, AN INDICATOR VISUALLY ACCESSIBLE TO SAID OPERATOR''S CAB, MEANS RESPONSIVE TO CHANGES IN POSITION OF SAID OPERATING BOOM TO MOVE SAID INDICATOR VISUALLY TO CONVEY TO SAID OPERATOR''S CAB THE POSITION OF SAID BOOM, A TOWER, MEANS MOUNTING SAID OPERATING BOOM AT THE PEAK OF SAID TOWER, SAID OPERATOR''S CAB AND ACCORDINGLY SAID INDICATOR BEING AT THE BASE OF SAID TOWER AND THUS SUBSTANTIALLY REMOVED FROM SAID OPERATING BOOM, AND LINKAGE MEANS INTERCONNECTING SAID INDICATOR AND SAID OPERATING BOOM OPERATIVE TO MOVE SAID INDICATOR IN RESPONSE TO CHANGES IN THE ANGULAR POSITION OF SAID OPERATING BOOM. 